This invention relates to photographic and cinematographic cameras, and more particularly to an optical system for providing an image of exposure condition indicia such as an adjusted value of the diaphragm of the objective lens in or at the image field of a reflex finder for the camera.
The presently available photographic and cinematographic cameras generally take on the exposure condition display to an increased number of exposure condition indicia for adjustment of the camera and in checking the actual voltage of an electrical power source or battery. This array of exposure condition indicia is required to lie in or near the focusing plane of the reflex finder optical system, or otherwise an image of the indicia will suffer a certain lack of sharpness as the finder optical system is designed so that a sharp image of the object area intended to be photographed can be seen at the focusing plane by the photographer looking through an ocular of the finder. Although it is desired that the indicia be located as close the object area as possible, the limitation of availability of a space which an exposure condition indicia display system is intended to occupy lead to a high possibility of requiring a large distance therebetween. If so, the image of the indicia will be seen far away from the field of view of the finder, thereby it being made more difficult for the photographer looking through the finder to read off the displayed values of the indicia with simultaneous performance of picture framing.
The main object of the present invention is to provide an optical system which enables an array of exposure condition indicia to be located at a desired large distance from a view-finder image, while nevertheless permitting an image of the indicia to be seen immediately adjacent the field of view of the finder by the photographer looking through the finder.
In one embodiment of the present invention as applied to a cinematographic camera having a reflex finder in which a beam of light forming a finder image is first focused at a plane before reaching the photographer's eye looking through an ocular of the finder, as the indicium array is positioned in or near the focusing plane at a long distance from the finder image field, use is made of light-deflecting means arranged in the path of light rays coming from the indicia, and oriented so that an image of the indicia can be seen immediately adjacent the field of view of the finder.